JPS6323995A - Rinse aid - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rinse aid for use in the rinse stage of a machine dishwashing operation.

In the case of mechanical dishwashing, the items to be cleaned are usually first washed in a main wash stage and then rinsed in one or more rinse stages, during which any adhering detergent components or remaining dirt are removed. removed.

The rinsing step allows the article to dry more evenly and has a better visual appearance when drying.
It is common to add a rinsing aid.

Without the use of the rinse aids described above, the appearance of the article after machine washing is often unfavorable due to the formation of spots during the drying process.

Koe-Rotsuba Patent Application NQ O139330 proposes that the use of a rinse aid containing a predetermined layered clay reduces the likelihood of spot formation on rinsed articles.

According to new findings, the incorporation of colloids such as colloidal silica or alumina in rinse aid compositions significantly suppressed spot formation during the drying process.

Additionally, it has been discovered that the use of colloidal non-plate-like particles, such as colloidal silica or alumina, in the rinse aid surprisingly reduces the drying time of rinsed articles.

Shortening the drying time is useful for dishwashing work using a machine, especially in industrial, production or institution
al) is very useful in mechanical dishwashing operations.

In addition to shortening drying times, incorporation of colloids of the type described above eliminates the need for conventional nonionic surfactant components, thereby reducing excessive buildup (which occurs when temperatures are lowered below the cloud point of nonionic surfactants). bubbles (over-roam)
) The temperature of the rinsing process can be lowered without facing the problem of ) and thus energy can also be saved.

fully formulated
It is known to incorporate colloidal silica into liquid detergent compositions.

FP 0110472 describes the use of silica as a corrosion inhibitor in aqueous liquid detergent compositions.

In TLS 3354088, amorphous silica is used as a flow retardant in aerosol-type aqueous window cleansers.

US 373B 259 and US 3919101 describe the use of silica in carpet cleaning compositions.

It is our knowledge that non-plate colloids such as colloidal silica or alumina can be used as anti-spot agents (
No literature has ever disclosed or suggested that it be incorporated into a rinse aid as an anti-spoC Hng agent or a drying time shortening agent.

The aqueous rinse aid compositions with superior anti-spot and drying properties provided by the present invention are characterized by the inclusion of an effective amount of non-plate colloids in the aqueous medium.

The present invention also provides a method for reducing spotting and drying time in mechanical dishwashing operations. A feature of the method is the addition of non-plate-like colloids to the dishwashing liquid.

As used herein, non-plate-like colloids include all particle-shaped colloids that do not have the characteristic that the size in one dimension is significantly smaller than the size in the other two dimensions. In particular, substantially spherical colloids are preferred. Examples of the preferred colloids mentioned above include silica, alumina, and titania.

Preferred colloids suitable for use in the compositions and methods of the present invention have relatively low average particle sizes, which are typical sizes for colloidal solution-forming particles.
elementary particle 5ize
), i.e. approximately 0.001 to 1- or 5 tones. In terms of effectiveness, the lower limit range mentioned above, especially 0.002-0.
051iIR is preferred.

The most preferred type of colloid for use in the present invention is colloidal silica.

Suitable silica is commercially available, and various grades of colloidal silica are available under the trade name Ludox (Ludox is DIJ
5yton (5yton is a registered trademark of Hon5anto Company), product name 5yton (5yton is a registered trademark of Hon5anto Co.
is a registered trademark of mpany)~, or the product name Ac
rosil (Aerosil is a registered trademark of Degussa).

Ludox is a precipitated silica and Aerosil is a flame hydrolysed silica.
ed 5ilica).

The colloid may be added to the rinse solution as such, or in the form of a colloid dispersion or a suitable rinse aid composition containing the colloid and a suitable conventional rinse aid component.

Colloid suspension in the rinsing liquid is approximately 0.5 per 11 parts of the rinsing liquid.
The nail contains ~150I1g of colloid.

The rinse aid composition of the present invention contains 0.2 to 25% by weight of colloid. Amounts of 0.5 to 10 ffi% are preferred, with 1 to 5% by weight of darkness being most preferred.

The rinse aid composition may optionally contain acid compounds, particularly organic acids such as citric acid, adipic acid, glutaric acid or succinic acid. Acid compound formulation m is up to 50% by weight
, preferably 5 to 30% by weight.

Using the colloid-containing rinse aids of the present invention, spot formation reduction rates comparable to those obtained by adding acids such as citric acid to conventional rinse aid compositions can be achieved without the inclusion of citric acid. obtain.

It is generally advantageous to be able to achieve the same effect without containing the above-mentioned organic acids.

Conventional ingredients suitable for inclusion in the compositions of the invention are hydrotropes such as butylated hydroxytoluene, alcohols, humectants such as nonionic surfactants, fragrances, disinfectants, corrosion inhibitors and colorants. .

It is particularly preferred to add short chain (eg C-C3) water-soluble alcohols to the rinse aids of the invention. It has been found that combining colloidal sols with certain conventional rinse aids can lead to the formation of precipitates. This phenomenon occurs, for example, when a dispenser is refilled with a different type of rinse aid while the previous rinse aid still remains in the dispenser. The amount of alcohol incorporated is up to 40% by weight, preferably 10-30% by weight, most preferably 20% by weight.
~30% by weight.

Rinse aids may be used in combination with conventional enzymatic or non-enzymatic main-wash products. The cleaning agent may be in any form, such as powder, liquid or tablet.

The rinsing aid is a two-dimensional agglomerated array (t
wo-dimensional aggregated
It should be understood that it may include (arrays).

The method for producing the agglomerates is described in US Pat. No. 2801902 and European Application No. 87303527.3 (Unilever
)It is described in. The columns are usually in the form of a compact single layer. The most preferred colloid exhibiting this behavior is silica sol.

Further explanation will be given below with reference to Examples.

EXAMPLES In the experiments shown in the examples below, glassware with standard stains was used to measure spot and haze.
The degree of formation of 1ll) was investigated.

Experiments were conducted using the following 8 commercially available food washes.

(1) Former ALE G 560 commercially available from former ELE & Cie in Germany ■Industrie 2anussi in Italy
Zanussi l 82 commercially available from Sp^ ■ Bosch-3iemens Hausg of Germany
Bosc commercially available from erLite Gmbll
h In the H500 cleaning bloc, tap water with a German hardness of 9° was used, and a main detergent for dishwashing hoe having the composition shown in the table below was used at a concentration of 3 g/l. As needed,
Rinse aid once (approximately 3 #ti! per 101 (6)
Added to final rinse.

After the main washing step and the rinsing step, the degree of spot and burr formation of the dried glassware was evaluated with the naked eye according to the following criteria.

1 = No spots 2 = 1 to 5 spots 3 = 6 to 10 spots 4 = 11 to 20 spots 5 - 20 or more spots 1 = No clouding 2 = Slightly cloudy 3 = Moderate cloudy 4 = Severe cloudy Example 1 Colloid The degree of spot and haze formation when various rinse aids consisting of aqueous silica dispersions were added was investigated by varying the concentration of colloidal silica.

All experiments were conducted using a Type 1 dishwasher, Type A main cleaner, and two final rinse temperatures.

The following results were obtained.

(1) Ludox 3M (RTH) is a DuPOntl silica with an average particle size of 7 nm.
30% by weight as Si02; counterion - sodium).

(2) Ludox TH (RTH) is DuPont! with an average particle size of 22 nm. ! 1 ] Oide silica (50 m F1% as S i 02; counterion - sodium).

(3) Ludox AH (RTH) is 0uPOnt [colloidal silica (S
30% heavy bottle as iO2; counterion = sodium).

1iJl Type 2 dishwasher, using Type B main cleaner 4
The degree of spot and haze formation of the rinse aid composition of the present invention was investigated after one or four repetitions of the program cycle at final rinse temperatures of 0°C and 60°C. The composition of the rinse aid is as follows.

The rinse aid composition used in Example 2 was then tested for spot and haze formation in a Type 3 dishwasher with a Type C or D main cleaner at a final rinse temperature of 55°C.

The following results were obtained.

Example 4 Swedish Electrolux-11ascat
Tail industrial Electrolux commercially available from or
The drying time of the final rinse was investigated for glass products that had been washed as usual at 60° C. using tap water with a German hardness of 8°.

The rinse aid of Example 2 was compared to three conventional rinse aids having the compositions shown below.

A rinse aid was added at a concentration of 0.29/I.

Experiments were conducted at three final rinse temperatures.

Drying times are given as ranges because drying times depend on the heat capacity and therefore the thickness of the individual glassware.

The following results were obtained.

Example 5 In a comparative experiment similar to Example 4, the foaming properties of various rinse aids were investigated. Foaming property was indicated by the height of foam from the water tank.

The following results were obtained.

Example 6 In another comparative experiment, differences in glass appearance depending on the type of rinse aid were investigated. A type 3 dishwasher was washed once or four times using the main type detergent. 2. The rinsing temperature was 65°C.

The following results were obtained.

Example 7 The stability of the rinse aid of the present invention when mixed with conventional rinse aid 1 was investigated. This experiment was to investigate the stability when another rinse aid was added to a dispenser in which the previous rinse aid remained. 25@ in the dispenser where at least 1/3 of the previous rinse aid has been consumed
Even with the addition of a Ludox-based rinse aid containing a large amount of isopropanol, flocculation
Few (<5%) cases were observed.

Example 8 Spot and haze of LLldOXSH rinse aid containing various weights of citric acid at 8 final bath temperatures of 65° C. using 26° French hard water, a Type 1 dishwasher, and a Type B main cleaner. The degree of formation was investigated.

Build-up after 4 cycles (bui 1d-up)
was evaluated.

Example 9 Spot and haze formation of Ludox-based rinse aids with and without citric acid was investigated using Type 1 dishwasher and Type C main cleaner.

The final rinsing temperature was 40°C or 60°C. Evaluation was made after washing once or four times. Comparison was made with conventional rinse aid 1.

The performance of the modified rinsing aid was investigated using various colloids.The main detergent B was washed at 60°C and then rinsed at 65°C.The amount of colloid used was expressed as the total surface area. .

LQpandin and eight crosil Dcgussa
It is a product of

The former is alumina and the latter is silica (Si 1C
asilicas). Dispersal is Co
It is a product of ndea and is made of alumina. Ludox SH
is a product of Du Pont and is silica.

Claims (4)

[Claims] (1) Rinse aid compositions suitable for use in aqueous rinse solutions containing non-plate-like colloids in the aqueous medium. (2) The composition according to claim 1, wherein the non-plate-like colloid is silica, alumina or titania. (3) The composition according to claim 1, which is a liquid further containing 10 to 30% by weight of C_1 to C_3 alcohol. (4) The composition according to claim 1, further comprising citric acid, a hydrotrope and/or a wetting agent.